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Mini ikea molgan hack

Update exactly 7 months after initial post: I have used this on my night stand, for a little bit of instant light during the night. The thing is still working, but visibly dimmer, the batteries are just under 1V each, so mostly discharged. 7 months is a pretty good life time.

This does not deserve so much attention, but here it is. I got one of the Ikea Molgan motion sensor lights and thought it is too bright for the application. The light has 5 LEDs inside and the tipical BISS0001 pir IC.

They were bright enough to use a current limiting resistor for each LED(the right way to do it), so there are 2 solutions: increase the resistor for each LED, or just leave a single one ON. I took the lazy way out and cut the trace after the first resistor.

Ta daaaaaaa!

In case you are wondering, the original lamp burns almost 70µA while on standby and almost 100mA while the LEDs are on. This gives you about 1.6 years of standby and 10 hours of light or however you manage to combine it(about 6 months at 5 triggers of 30 seconds per day). With this change the light time is increased to 5X, so about 50 hours.

Too bad they used AAA batteries, AA would have been slightly larger, but with 2.5 times the life.

My guess is that U2 (and surrounding components) is the touch sensor, U1 is the LED driver and U3 is the control circuit. U1 probably has some enable signal. Depending what you want to achieve you could either just force U1 to be always on or replace U3 with something else that gets you the light always on as long as there is some touching.

What are you trying to get? Can you read the markings on U1, 2, 3? (I cannot find any info)

I saw the Stotta (in fact, I was there today hoping that maybe the Molgan was going to be on sale – no luck).
The bar form factors are interesting, but I think I remember them being the cooler temperature light.

I have an wish list of items waiting in a cart on FastTech that includes a couple of their very inexpensive PIR sensors… pretty much cuts it down to the minimum PIR sensor and controls, for < $2. I'm holding off because I keep thinking "when will I ever actually get around to DOING anything with them". Sad. I have so many parts I've picked up over the years in a fit of enthusiasm and they wind up in my "someday" pile… Arduinos, including the little mini's, half a dozen STM85 boards, a couple of VO2 sensors, handfuls of power LEDs on stars, bluetooth boards, wifi equipment. Big dreams, temporary enthusiasm, smaller motivation. 🙁
But, at long as I have 'em, I can always "do it one day". 😀

Yeah, PIR sensors are pretty cheap now. The ones i have from some years ago when the price was $3-4 proved reliable, but I already see more stuff cut from newer versions.

I understand your parts collection – I have it too. It’s more of a “i’ll get 5 of these, even though I need only 2, to use later”. I miss the days when all I had was the local electronics shop. Wanted to make something … went there and figured out how to with just what was available.

My wife saw it and wanted me to try it in the downstairs coat closet. She loved the motion-sensing and warmth of the LEDs. I had to pick up a second to fill out the closet illumination. (Actually, I cheated and picked up a third that she doesn’t know about – one day I may get around to hacking on it.)

I use the Ikea cheap NiMH AAA’s in it (800 mAh). I agree, they should have made it a AA-sized case for practicality.
Maybe that will be my first hack attempt.

There is another version, STÖTTA which uses 4x AA batteries intended for wardrobe. It is brighter, but it does not have a light sensor. I had one at some point, but the batteries died pretty fast and I was not able to open it. Normally PIR ICs have the functionality of light sensing in them, it is just a matter of adding a photo diode/resistor to get it to work in the dark only.
Rechargeable batteries are better, but i find it complicated to manage to keep them charged and changed often.